1. Field of the Invention
The present invention relates to a laser measuring system for industrial inspection in which a laser beam is scanned across the surface of an article and, more particularly, the present invention relates to a laser measuring system for industrial inspection which collects light of a scanning beam reflected from the surface of an article in an imaging lens which focuses the reflected light onto a optical grating for determining a contour of the surface of the article.
2. The Prior Art
Reference is made to U.S. Pat. No. 3,975,102 issued to Rosenfeld et al. on Aug. 17, 1976 and entitled "Scanning Photoelectric Autocollimator." Rosenfeld shows and describes an apparatus which is adapted to measure the surface profile of some specific objects utilizing a coherent light source and a two dimensional photoelectric position sensor. The beam of coherent light is directed onto a rotating set of mirrors which provide a raster scan which is directed toward the article to be scanned. The beam is reflected and directed through a polarization beam splitter onto the position sensor. The location of the beam on the position sensor is utilized by a processor to determine any irregularities in the contours of the object. The surface being scanned must be of a concave or convex nature or some other known shape such that lenses are provided which allow the beam directed at the surface and the beam reflected therefrom to coincide.
Rosenfeld and the other constructions known in the prior art do not show a system in which a laser beam is scanned across an article and a lens collects diffuse reflected light from the article surface and focuses that collected light onto an optical grating having alternate transparent and opaque bars.